String Quartet Transposition

[Tony]

I come from a British Brass Band background and am quite befuddled by any transposition other than from piano to Bb :-) I would like to transpose some string quartet music so it could be played by any combination of B flat instruments. There seem to be several approaches and I would like your opinion as to which is the preferred approach. Could you also provide guidelines (idiot level) for whichever approach you recommend? Here is what has occurred to me.
1. Leave the violin parts as is for the trumpets. Transpose the viola for Euphonium (BC and TC) and transpose the cello part for Tuba (BC).
2. Leave the cello part as is for the tuba and transpose the violin parts for the trumpets and the cello part for the Euphonium (BC and TC).
What do you recommend and how do I proceed?

[highpitch]

Anything in bass clef for strings can be played by bass-clef euph & tuba without change.

Treble euph will need transposition, tenor clef as sometimes found for cello can be read as treble clef with appropriate accidentals.

Violin is usually scored in treble in concert pitch, violas in alto clef. Transpositions necessary for treble-reading brass in Bb.

Dennis